The River Moriston, near the Dundreggan Estate. Scots pine and other native trees grow along the river, but much of the glen is given over to commercial conifer plantation of low biodiversity value. Photo: Philip Mason.

One tree at a time: restoring the forest of Caledon

Scotland's native forest remains in only a few fragments, but Trees For Life is working to restore it, and almost all of the work is done by volunteers. Philip Mason joined their newly expanded long-term volunteer programme for two months last autumn.

It's not these trees that make the forest, but their progeny. We are setting a forest in motion.

Looking out from a high spot in the mountains west of Loch Ness, a river runs through conifer plantation below, and a fringe of ancient birchwood clings to the steep sides of the valley.

Beyond, the bare hills roll away to the horizon. They are beautiful, yes - what a place to come to work! - but they are also naked.

Reduced to fragments

The once great Caledonian Forest covered most of upland Scotland: 5,800 square miles of species-rich boreal wilderness. But a long history of felling, burning and over-grazing has reduced the Forest to mere fragments.

Looking at a landscape of this great scale, I find it difficult to imagine that anything I can do will have much effect. Not so Trees For Life, a group dedicated to rebuilding the Caledonian Forest from the ground up.

And here on TFL's 10,000 acre Dundreggan Estate, and at other sites around the Highlands, my fellow volunteers and I are rolling up our sleeves as we get down to our day's work.

Exotics out!

There's more to restoring forest than planting trees. There's also getting rid of the ones you don't want. In this case it's hemlock, sitka spruce, lodgepole pine: fast growing thugs brought here from North America and Scandinavia as timber crops decades ago.

They are fine enough trees in the right place, grown in mixed age, mixed species stands. But not here, where the over-riding conservation priority is to regenerate Scots pine from the few remaining ancient trees,

Long after the original military ranks of exotic conifers were felled out, their offspring continue to grow from seed in the soil - clogging the understorey, blocking out the light, and inhibiting the growth of Scots pine seedlings.

We cut the unwanted trees down with hand saws, or rip them up by the roots, sweating, swatting at midges with hands sticky with sap. It's vigorous and satisfying work, and progress is satisfyingly fast.

At the end of the day another patch of pine forest is looking as it should: light reaches the ground, and the native Scots pine seedlings have the room they need to grow.

Mapping the terrain

Then there's mapping to do. We go on long hillwalks in small spaces, GPS units in hand. Traversing a single hillside, back and forth, many miles in a day, plotting the growth of bracken fern. Then walking in circles, round and round, tracing out where trees will be planted.

There's time to take in the view, the changing colours of the landscape. As autumn comes, the bracken fades from green to yellow to rust red. Three golden eagles catch a thermal above us one lunch time.

Perhaps a little seed collecting if we're lucky: acorns, hazelnuts, birch catkins, rowan berries. A happy and peaceful activity, something of the ancient harvest, gathering in so much potential.

It becomes compulsive - enough so to lean out over a sharp ravine for one more fistful of berries, or tumble headfirst down a stony bank to get at some hazel.

Wilderness in your hands

We roll up our sleeves and chat while we crush the red rowan berries in buckets of water, to release the tiny seeds. The smell is earthy and sharp, like some wild wine fermenting. Seed gathering feels like the start of good things.

Some of the more mundane work also falls to us from time to time: sharpening tools, splitting firewood, strimming paths. We have to remain flexible. Out in all weathers, rough underfoot, always up or down, never flat.

At first we arrive home exhausted each day, sometimes discouraged, but stamina grows in time, and we enjoy our evenings more and more. Cooking for each other, sitting out by a fire, making music.

Friendship quickly deepens, and the little ramshackle cottage becomes our home as we decorate it with drawings and driftwood collected on a day out. In the morning we try to remember whose turn it is to feed the boar.

All the trees of the forest

In the nursery, where all the trees for the project are grown, the polytunnels are good for getting out of the rain. At long benches we sort, count, pack and label the trees, ready to go out onto the hill.

In the yard outside, tray after tray of seedlings wait. Downy birch and rowan, the pioneers. Scots pine, the cornerstone of this new forest. Juniper, sharp-needled and fragrant. The aspen, difficult to propogate, so long-lived it doesn't care to set seed very often.

Montane willows, low-growing and modest, are among our rarest trees, critically endangered in the Highlands. Dwarf birch, knee high, easy to miss, hanging on here while lost from much of Scotland. Here in the nursery each seedling is coaxed on. None are wasted.

All of this is good work, but it is of course the tree planting that feels like the heart of the matter, and as the season progresses this becomes our focus. Each morning we shoulder our spades and make the long walk out onto the treeless hills, no shelter from sun, wind or rain.

The battle is hard

The trees we plant are small, perhaps 12 inches tall or so, and one or two years old. Each needs genuine care. Everything seems to be against them up here: hungry deer, waterlogging, freeze-thaw, nutrient-poor peat.

Mechanical diggers have prepared a spot for each, a patch of ground clear of competition from grasses and heather, better draining and much faster to plant into. A fence keeps out the deer until the trees have grown, and next year more volunteers will come through and give each one a cup of rock phosphate fertiliser.

All this is laborious and expensive, but gives the trees the best start. Beyond that, well, they know what they're doing. They belong here.

As for us, skill comes with practice. I remember the first day I planted a hundred. I remember the only day I planted five hundred. The days when we were behind schedule, with the hard weather coming on, and the days when we were on form and catching up.

One tree at a time, a forest is set in motion

Keeping count helps it feel less like a drop in the ocean, and more like progress. A slow, steady advance, tree by tree, week by week, acre by acre across the hillside. Birch, rowan, alder, aspen, bird cherry, Scots pine. Two months, a great many volunteers, and 15,000 or so trees in all.

The scale of this denuded landscape can be overwhelming, but a mouse eats an elephant one bite at a time, so they say. It's not these trees that make the forest, but their progeny, generation by generation through time.

The other plants will follow; cowberry, twayblade, glittering wood-moss. Invertebrates and birds, and surely one day the missing boar, perhaps even lynx, bear and wolf. We're not planting trees, but setting a forest in motion.

Trees for Life is one of Scotland's leading conservation volunteering charities. Founded in 1989, their vision is to restore Scotland's ancient Caledonian Forest to a wilderness region of 1,000 square miles of mountains and glens to the west of Inverness and Loch Ness.